Method and system for localization of targets using SFCW MIMO radar

Patent metadata

Field	Value
Publication number	US-12535569-B2
Application number	US-202318465786-A
Country	US
Kind code	B2
Filing date	Sep 12, 2023
Priority date	Feb 16, 2023
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

Conventional ESPRIT (Estimation of Signal Parameters via Rational Invariance Techniques) cannot be directly applied to SFCW MIMO radar for localization of targets as the performance would be restricted by geometry of spatial MIMO. Thus, the present disclosure provides a method and system for localization of targets using SFCW MIMO radar. In this method, the channel response of the virtual uniform rectangular array (vURA) obtained by scanning at uniformly spaced frequency points is combined to form a larger array referred as Space-Frequency (SF) array. The 3D localization of targets is done by estimating azimuth angle, elevation angle and range using this SF array. The localization capability of the disclosed method largely depends upon the number of frequency scanning points and enables localizing far more targets than the dimension of the vURA. In addition, the inter-element spacing requirement of vURA is also greatly relaxed.

First claim

What is claimed is:

1 . A process implemented method comprising:
receiving, via one or more hardware processors, a channel impulse response H(m) captured by a Stepped Frequency Continuous Wave Multi-Input Multi-Output (SFCW MIMO) radar comprises a uniform linear transmitter array and receiver array of dimensions N y and N z respectively that are orthogonally arranged, providing a virtual Uniform Rectangular Array (vURA) of dimension N y ×N z , wherein d y and d z denotes an inter-element distance of the vURA along y-axis and z-axis, respectively, wherein increasing the inter-element distance overcome effects of mutual coupling; computing, via the one or more hardware processors, a covariance matrix R SF from the channel impulse response; performing, via the one or more hardware processors, eigen value decomposition of the covariance matrix to obtain a signal subspace matrix U s comprising eigen vectors corresponding to a pre-defined number of largest eigen values of the covariance matrix; constructing, via the one or more hardware processors, a pre-defined number (N μ ) of sets of transformation matrices, wherein each set of transformation matrices comprise a left transformation matrix

β
left
μ

and a right transformation matrix

β
right
μ

computed based on a first identity matrix I N f with its first diagonal element as 0, a second identity matrix I N f with its last diagonal element as 0 and a binary matrix J μ with only the element at (μ, μ) as 1 and rest of the elements as 0;
computing, via the one or more hardware processors, a plurality of transformed signal subspace matrices ϕ μ based on the sets of transformation matrices and the signal subspace matrix;
calculating, via the one or more hardware processors, a sum of the plurality of signal-subspaced transformational matrices and performing eigen value decomposition on the sum to obtain a rotational signal-subspaced transformational matrix T R ;
determining, via the one or more hardware processors, a parameter matrix Ω μ from the rotational signal-subspaced transformational matrix;
estimating, via the one or more hardware processors, azimuth angle, elevation angle and range of each of a plurality of targets from the parameter matrix to localize the plurality of targets; and
dynamically adjusting only number of scanning frequency points N f and relaxing the inter-element distance of the vURA facilitates localizing the plurality of targets with a fixed dimension of the vURA.

2 . The method of claim 1 , wherein the channel impulse response (H(m)) is a space frequency array of signals reflected from a plurality of targets at m th snapshot calculated by the equation-

H
⁡
(
m
)

=

(

a

y
,

z
⁡
(

f
0

,

θ
0

,

Ø
0

,

R
0

)

…

a

y
,

z
⁡
(

f
0

,

θ

L
-
1

,

Ø

L
-
1

,

R

L
-
1

)

a

y
,

z
⁡
(

f
1

,

θ
0

,

Ø
0

,

R
0

)

Assignees

• Tata Consultancy Services Ltd

Inventors

• Kumar Achanna Anil
• Rokkam Krishna Kanth
• Chakravarty Tapas
• Pal Arpan
• Gigie Andrew

Classifications

• G01S13/42 Primary

  Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S13/46) · CPC title

• G01S7/352

  Receivers · CPC title

• G01S13/006 Primary

  Theoretical aspects (G01S7/418, G01S13/9094, G01S13/958 take precedence) · CPC title

• G01S13/584

  adapted for simultaneous range and velocity measurements · CPC title

• G01S13/38

  wherein more than one modulation frequency is used · CPC title